Wetmore



Dec. 1%, 1929., E. P. WETMORE METHOD AND APPARATUS FOR BURNING FUEL Original Filed Oct. 25, 1924 Nv QM, av m l n: s f NM. QM. QN NW NW NW w. aw m, i a QZE V Uj I I. I M I 1 V5.2 ,2 Q V ATTORNEY iplastic fuels ofsimilar nature.

Patented Dec. 10, 1929 i UNITED STATES 'EARL P. WETMORE, OF. CONCORD, MICHIGAN, ASSIGNOR TO THE ANOILCOAL BURNER [PATENT OFFICE 00., or TOLEDO, OHIO, A CORPORATION OF DELAWARE METHOD AND APPARATUS FOR BURNING FCEL Application filed October 23, 1924, Serial No. 745,309. Renewed May 4, 1929.

I This invention relates to a method and apparatusf for burning fuel and, more particularly, to a burner adapted to'form a readily combustible suspension in air of fuels of a semi-fluid nature, such. as the stiff pastes formed; of solid and liquid fuels, or of ther Composite fuels of this type are commonly formed of minuteparticles of powdered fuel,

from which the. ash-may have been removed I to a greateror less extent,and of a liquid fuel whichsurrounds the particles with, a' film or layer of oil and serves to unite the particles into a coherent paste, of a nature intermediatethatof the solid and liquid fuels of which it is composecLdand having character- 'istics different from its solid and liquid constituents: The stiffness and consistency of these pastes may vary with the proportions and characteristics of their constituents, being usually of sufficient stiffness that they do not flow readily, and maybe burned on a suitable grate in the manner of solid fuels. Because of the greater flexibility in control and in the adjustment of the-air supply obtained in the combustion of fluid fuels, and to the greater ease 1n burning, and consequent greater efficiencies in combustion, it is highly desirable to burn such fuels in a flame in the manner Of-fluid fuels by atomizing and diffusing them into a current of air in such a mannerthat they maybe readily ignited and burned. Owing to the physical characteristicsof the composite fuels' of the above mentioned types, they cannot be handled in quite the same manner as liquid 'fuels, which flow readily, may be projected in jet form and are readily brokenup to a mist, nor in the manner of powdered fuels, which are already in a fine state of division and partly mixed with air. Anobject of my present invention is to provide amethod and apparatus which will enable fuels of'the above indicated types and characteristics to be burned in a flame in a -manner similar to fluid fuels.

Another object of the invention is ,tQprovide an;appa ratus by, which the supply of air for-supporting the combustion of the fuel may be readily controlled and adjusted to the requirements of the fuel.

A still further objectofthe invention is to provide an apparatus for burning fuels of,

tionately controlled or regulated in accordance with the'rate of supply of the fuel.

' lVith these and other objects in view, which may be perceived from the further and detailed description of the invention, the'invention comprises the method and apparatus described and set forth in the following specification and claims.

The various features of the invention are illustrated in the accompanying drawings, in which Fig. lis a view in side elevation of a burner emiiodying a preferred form of the invention, an

Fig. 2 is a-sectional view of the burner, taken on line 2 2 of Fig. 1.

In my present invention, fuelis forced, in a continuous manner, through a supply .passageway by a suitable conveyor means, such as a screw conveyor, and through a narrow orifice to issue-as a thin sheet or ribbon. A jet of gaseous flinch-preferably air, is. directed across the path of the sheet of fuel as it issues from the orifice" and closely adjacent the outer face of the orifice, so that the front, advancing, edge of the sheet of fuel is sheared OE and carried into the jet, the pressure of the air and velocity of the jet being sufficient to thoroughly disintegrate the body-v of fuel, separating the particles of solid fuel from each other, and carry the separated particles with their films of oil in a fine suspension in the current of air. The issuing ribbon of fuel is preferably'annular inshape and the jet of air is directed inwardly, forcing the'separated particles of fuel into a central stream of commingled air and fuel which thence passes through a nozzle into a furnace in which it is burned. A supply of secondary air is introduced into the nozzle to complete the requirements of the fuel for oxygen for combustion and the entrance of this air is controlled with that of the primary jet through a mechanism that varies the opening and closing of the supply of primary and secondary air simultaneously and in direct proportion to each other.

Referring more particularly to the accompanying drawings, a supply of the composite fuel paste is placed in a'hopper 10 mounted on, and opening downwardly into a horizon- ;tal conveyor tube 11, the adjacent end of the tube ng cles rl by a p at 2 e d o th end of the tube wall by screws 13. The fuel sinking into the end portion of the tube 11 from the hopper 1.0 is conveyed forwardly in the tube by mea is of a screw conveyor 14 rigidly mounted on a rotatable shaft 15, one end of which projects outwardly through, and is supported in, the end closing plate 12. T he shaft 15 and conveyor 1% may be driven by any suitable means, such as a worm 16 and gear 17 mounted on the end of the shaft projecting outside of the plate 12.

i The opposite, forward, end of the shaft 15 ,is journaled in a supporting hearing member 18 supported centrally in the forward portion of the tube 11 by means of radial arms 19 secured in the wall of the tube. The bearing support 18 flares outwardly at 20 at its forward end in front of the arms 19 to within a short space of the inner surface of the wall of the tube 11 to form a narrow annular opening 21 and the fuel paste being forced forwardly by the screw conveyor 14 is forced by the all 20, which acts as a mandrel or triblet, into and through the annular opening 21. A thin annular wall or ribbon of fuel is thus formed and issues from the front edge of the orifice in position to be acted on and disintegrated by a ct of air or other suitable gas.

F or this purpose, air under pressure is supplied through a pipe 22 to an annular cham ber 23 surrounding the end of the tube 11 and encircling the wall or sheet of fuel issuing from the annular orifice 21. An annular jet orifice 24 is formed in the inner peripheryof the annular chamber 23 atthe end of the wall of the tube 11 through which the air under pressure within the chamber 23 issues at a high velocity and intersect-s thepath of the fuel from the orifice ataright angle. The pressure of the air supplied tothe cli'ai'i'iber 23 imparts sufficient velo city'to' the jet issuing through theorifice 2d to' continuously shear the forward end of the wall of fuel as soonas it passes beyond the front edge of the tube 11, tearing apart the'ininute particles of which thef-ul is composed and carrying-them into the jet. A pressure of'from fifty to one hun} dred pounds ordinarily sufficient for this purpose. A jet of air carrying the finely divided, separated particles of which the fuel is composed, covered with their films of oil, converges inwardly from the orifice 2% towards the axis of the tube 11 and then expands forwardly into a nozzle or combustion chamber 25 from which the commingled fuel and air is dir cted to the combustion chamber of a furnace. To assist in deflecting the jet forwardly, a cone 26 is mounted with its base on the forward face of the triblet 20 and with its tip pointing towards the throat of the nozzle.

The nozzle 25 is preferably of the Venturi type having a contracted throat portion 27 and a flaring portion 28 leading tlIQIQfiOH'l. In passing through the throat 27, a slight vacuum is produced in the current of air and suspended fuel which serves to draw a supply ,of secondary air through inlet openings 29 into the throat of the nozzle to supply whatever additional oxygen may be required for the complete combustion of the fuel. The quantity of air admitted through the openings 29 may be controlled by means of an annular damper or band 30 slidably mounted on a cylindrical surface 31 on the outer face of the nozzle and slidable to partly or completely close the openings 29.

The size of the jet of air issuing from the orifice is preferably adjusted in accordance with the rate at which fuel is forced by the screw conveyor 15 through the orifice 21. For this purpose the chamber is preferably formed in a rearward extension 32 of the nozzle member 25 and is provided at the rear of the chamber 23 with a rearwardly extending annular flange or wall 33 telescoping over the forward end of the tube 11. Extending, radially inwardly from the chamber 23 is a face 34. spaced from the end of the tube 11 to form the orifice 24: and spaced from the end of the tube 11 a distance depending on the position of the nozzle 25 on the tube 11.

To adjust the position of the nozzle 25 on the tube 11, the outer surface of the flange 33 is tl'ireaided to receive internal threads on a collar 35, which also extends over and is threaded on an outwardly projecting shoulden 36 on the outer forward wall portion of the tube 11 and which is threaded in an op.- po i s -setien fr m he threa of t zle 25. The screwth eads on the flange 33 a s eul l r 36 a e thu ela y r gh handed and left handed to each other so that as the collar 35 is rotated in one direction or the other, as by means of a lilandle 37, the nozzle member and the shoulder are moved towards or from each other, As the shoulder 36 is rigidly mounted on the tube 11, the face 34 is accordingly brought to or from the end face of the. tube 11 and the size of the orifice .2 ied e rd neln T e a en y c airdi-awu threughtlle open lift r the damper band on the nozzle 25 as the tween cars 42 on the nozzle 25 which holds the,

'rods fixed in relation to the circumference of the nozzle but permits them toslide longitudinally. jAs the collar v35 and cam grooves 88 are rotated, therefore, the rollers 39, held in fixed peripheral position relative thereto, are caused to slide longitudinally, the cam grooves being in such relation to the thread- .ing of the flange 33 and shoulder 36 that the damper band 30 is drawn to closing position as the face 34 is moved towards the end of the tube 11 to narrow the orifice 24, fillClTSO proportioned that the movement of the face 34 and the damper band 30 are proportional; y,

Through the above invention, therefore, a fuel paste of the type. indicated may be spread into a thin sheet or wall and fed for wardly at any desired rate, and the forward, advancing edge may be sheared oif and dis integrated into the particles of which the fuel was formed by a jet of air which at the same time carries the separated particles of fuel in v a finely divided state permitting rapid ignition andcombustion. The quantity of air" in which the particles are suspended is also automatically proportioned to supply thewithin the scope of my invention, it is desired that all matter contained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not in a limiting sense- Having described my invention, what I claim and desire to secure by Letters Patent 1 A method-of burning fuel which comprises, directing an annular jet of air radially inwardly, feeding a fuel paste in the form of an annular sheet into said jet whereby particles of fuel are sheared off from said an nular sheet as it enters said jet'and are carried in suspension, and conveying said air and suspended fuel into a combustion chamber. 2. A method of burning fuel which comprises, forcing a fuel paste through a longitudinally disposed annular orifice and directblast of air radially inwardly across the outer edge of said orifice to shear off and car- -arranged annular-outlet orifice, meansin said ry in suspension particles of said fuel as they issue from said orifice.

3. A method of burning fuel which comprises, forcing fuel paste through a longitudinally arranged annular orifice, directing a blast of air across the outer edge of said orifice toward the innerv edge thereof to shear off and carrying in suspension particles-of said fuel as they issue from said orifice, and varying the cross-sectional area of said air blast in proportion to'the rate of supply of said fuel paste. 7 7

4. A fuel burner which comprises a fuel feeding passageway having a longitudinally passage for advancing fuel therethrough and wardly across the outer edge of said orifice whereby said edge is continually sheared ott'.

6. A fuel burner which comprises a longitudinally arranged annular orifice, means for 5 feeding fuel paste throughsa id' orifice, means for directing a jet of air radially inwardly across the outer edge of said orifice whereby said edge is continually sheared off, and a nozzle receiving the air and suspendedfuel i'oo from said orifice and jet.

7. An fuel burner which comprises a conveyor tube having a longitudinallyarranged annular outlet orifice, means for conveying fuel through said tube and forcing it through said orifice, an air chamber encircling said orifice and an outlet from said air chamber opening inwardly towards and across the'outer edge of said fuel orifice. p

8. A fuel burner which comprises a conveyor tube having a longitudinally arranged annular outlet'orifice, means for conveying fuel through said tube and forcing it through said orifice; an an -amber encircling the outer portion of said tube and 15 having a jet orifice directed annularly inwardly across the path of fuel issuing from said fuel orifice, and a nozzle receiving air and fuel from said orifices.

9. A fuel burner which comprises a con- 12o veyor tube having a longitudinally arranged annular outlet orifice at its outlet end, a nozzle at said outlet having an edge juxtaposed and slightly spaced from the end edgeof said tube to form an'annular opening, a chamber 1 5 formed on said nozzle member and opening through said annular opening adjacent the edge of'said annular tube outlet orifice means forforcing air through said annular opening I and across saidannu'lar "orifice, and means 139 for forcing fuel paste through said tube and annular orifice.

10. A fuel burner which comprises a conveyor tube having an annular outlet orifice at itsoutlet end, a nozzle at said outlet end having an edge juxtaposed and slightly spaced from the endedge ofsaid tube to form an annular et opening, means for slidingsaid nozzle longitudinally on said tube tovary the size of said annular jet opening, an air chamber formed on said nozzle and opening through said annular jet opening, and means for forcing fuel paste through said: tube and said annular outlet orifice.

11. A fuel burner which comprises a con veyor tube having an annular outlet orifice at its outlet end, a nozzle: at said outlet end having an annular flange telescoping over the end portion of said tube, an annular chamber encircling the end of said; tube, and a face juxtaposed to and; slightly spaced from the end edge of said tube to form a jet orifice from said an-i-iul-ar chamber, andmeans for moving said nozzle and flange longitudinally on said tube to vary the opening of said jet orifice.

12-. A fuel burner which comprises a con, veyor tube having an annular outlet orifice at its outlet end, conveyor mechanism in said tube to force fuel through said annular outlet orifice, a nozzle at said outlet end having an annular flange telescoping over the end portion of said tube, an annular chamber en circling the-end of said tube and a face juxtaposed t'o, and slightly spaced from said an.- nular chamber directed at an angle to; the fuel outlet orifice, and means for moving said flange longitudinally on said tube to draw said face to or from said tube and vary the width of said jet, orifice.v

1-3. A fuel burner Which comprises a conveyor tube having an annular outlet orifice its outlet end, conveyor mechanism in said tube to force fuel through; said; annular orilice, anozzleat said outlet end of said tube having an annular flangetelescoping over the end portion of said" tube, an annular chamber encircling the end of said tube and a face juxtaposed to, and slightly spaced frormthe end edge of said tubeto form a ct orifice from said annular chamber directed at an angle to the fuel outlet orifice, and a collar threaded on said flange and the adjacent portion of said tube to move said flange longitudinally on said tube.

14. A fuel burner which comprises a conyeyor tube having an annular outlet orifice atits outlet end, conveyor mechanism in said tube to force fuelthrough said annular orifice, a nozzle at said outlet end of said tube having an annular flange telescoping over the end, portion. of said tube, an annular chamber encircling the. end of said tube, a face juxtaposed to, and slightly spaced from, the end edge,- of. said tube. to form. a, jet orifice maaos from said annular chamber directed at an angle to the fuel outlet orifice, and air inlet openings in the portion of said nozzle projecting forwardly from said tube, a damper for said air inlet openings, and means for simultaneously moving said flange and shoul der longitudinally of said tube and moving said damper.

15. A fuel burner Which comprises a con veyor tube having an annular outlet orifice at its outlet end, conveyor n'icchanism in said tube to force fuel through said annular orilies, a nozzle at said outlet end of said tube having an annular flange telescoping over the end portion of said tube, an annular chamber encircling the end of said tube, a face juxtaposed to, and slightly spaced from the end edge of said tube to form a jet orifice from said annular chamber directed at an angle to the fuel outlet orifice, and air inlet openings in. the portion of said nozzle projecting forwardly from said tube, a damper for said air inlet openings, a ring threaded on said flange and the end. portion of said tube to. move said nozzle longitudinally, and means actuated from said ring for moving said damper.

16. A fuel burner which comprises a conveyor tube having an annular outlet orifice, means in said tube to force fuel through said outlet, an annular chamber encircling the end portion of said tube and said annular orifice, a face forming with the end of said tube a jet orifice from said annular chamber and means for moving said face to or from said end of said tube to vary the size of said jot orifice.

17. A fuel burner which comprises a conveyor tube hawing an annular outlet orifice, means in said tube for forcing fuel through said outlet orifice, a nozzle on the outlet end of said tube having an annular chamber encircling the end portion of said tube, a face on said nozzle forming with the end wall of said tube, an annular jet orifice fron said annular chamber, air inlet penings in the nonzle portion of said nozzle, a damper for said openings,means for moving said face to and from the end of said tube to vary the width of said jet opening, and meansfor sin'lultaneously moving said damper.

In testimony whereof. I affix my signature.

EARL r. art roan. 

